LEGIT: electric supercharger mated to larger turbocharger from BorgWarner...
in 2016 BW's R&D department put out this video of what their team was working on, but just last month they had the below press release that they are really REALLY in mass production for this technology now!!!!! Twin-charging isn't new but using an electric centrifugal compressor(supercharger) is revolutionary and it will save you fuel and pollute less.
[ame="https://www.youtube.com/watch?v=eXWAPNOAuv0"]eBooster® Electrically Driven Compressor - YouTube[/ame]
https://www.borgwarner.com/en/news-m...rates-premiere